The grip panel areas of the Gen3 RTF2 Glocks have small raised pyramid-shaped polymer projections, at a linear density of about 20 per inch (around 400 per square inch; gun is a Glock 17 Gen3 RTF2).

The same areas of the Gen4 Glocks have larger, flat-topped pyramids at a linear density of about 12 per inch (approximately 144 per square inch; gun is a Glock 22 Gen4).

In addition to the differing shape and densities of the pyramids, there is one more significant difference -- on the Gen3 RTF2 guns, the gripping pattern is extended into the thumb-rest area of the grip (see the photo in post #1 at the top of this thread for a side-by-side comparison of the two frames). While it may or may not be helpful in adding to the security of the shooter's grip, it has been the source of some complaints about an abrasive "sandpaper" effect on certain areas of the shooter's thumb, especially when expending large quantities of ammo in a short time (examples: competitions and Law Enforcement qualifications).

One of the great advantages to the Glock series of pistols is the ability to use magazines of larger capacity than the stock magazine. There are two ways this can be accomplished; by extending the factory magazine using special magazine floorplates, or by using a longer magazine originally designed for another (larger) Glock of the same caliber. Obviously, other pistols made by other companies also share this feature, but I believe Glock offers more factory options in this area than any other maker.

Adding to the capacity of a stock magazine by replacing the floorplate with a "+" floorplate (or buying a magazine already equipped with one) is a popular option. The original extended floorplates were called "+2" (plus two) floorplates (which was stamped on the base), and added two rounds of capacity to a stock 9mm magazine. When the .40 caliber Glocks were added to the 9mm line-up, it was discovered that the +2 floorplate only added one round of capacity to the .40 magazines, due to the larger diameter of the .40 caliber cartridges. This was a little confusing for some folks, as they desperately tried to cram 2 more shots into their +2 modified .40 caliber mags, without success. Adding to the confusion, the plus-two floorplate was made in two versions; one for the older non-full-metal-lined (NFML) magazines, and another for the new/improved full-metal-lined (FML) mags, and although they appeared the same, they were not interchangeable.

At some point during the production of Gen3 Glocks, the extended floorplate was redesigned and the designation was changed to the "+" (plus) floorplate, which was (as above) also marked on the bottom. Now that it is a little bit deeper and with a slightly different profile than the original "+2" floorplate, it adds two rounds of capacity to all Glock factory 9mm, .40, and .357 magazines. Certain magazines can be purchased with a plus floorplate and insert already installed by the factory (G26, G27, and G18, for instance); others are available to Police/Military users as a complete item, but are not found on the "civilian" market here in the USA (although they can be legally created in most states by buying and adding the "extension" (#SP07151) and "insert" (#SP07165) parts to an existing magazine). Here are some comparison photos of the old- and new-style parts:

And two photos of a Glock 26; one with a normal 10-shot factory magazine, and the other with a factory magazine using the new-style "+" floorplate installed:

Other companies offer extended magazine floorplates, some with very large capacities (+6 or more rounds!), but I'm only concerning myself with factory options in this post. For more information on aftermarket accessories, check the Glock Talk discussion forums.

Using a longer magazine in your Glock is the other way to add capacity. Glock wisely made sure that all the guns in each "series" of frame size/calibers had the same basic magazine dimensions from the locking notch to the feed lips, allowing the use of any magazine long enough to fit and lock into the magazine well of the frame. This was a thoughtful design option originally aimed at the Law Enforcement market; if an officer carried a full-size Glock as their primary duty weapon, they could also carry a smaller Glock as a back-up weapon, and be able to use the full-size magazines on their duty belt for reloading either weapon in an emergency. It also made perfect sense for streamlining the manufacture of the magazines of various lengths for different models.

For the 9mm full-size guns, there is really only one option that is longer than the stock magazines; the G18 magazine. Originally designed to hold and dispense 31 shots for the fast-firing Glock 18 fully-automatic machine-pistol, the latest versions include the "+" floorplate discussed above to increase capacity to 33 shots. For the .40 caliber full-size Glocks, there is a recently released large-capacity magazine that holds 22 rounds of .40 caliber ammunition (also using a "+" floorplate). Although there is nothing specifically offered from the factory for .357 fans, I am told the .40 caliber 22-shot extended magazine works just fine with .357 ammunition.

For the smaller (shorter-gripped) Glocks in the compact and subcompact lines, the magazines from any larger (taller grip frame) Glock in the same caliber will fit and function normally. To illustrate, I have some photos showing a Glock 26 in 9mm caliber, and some of the magazines that will fit and function in it. The model numbers are different, but the same holds true of the .40 and .357 caliber Glocks of comparable sizes.

Glock 26 with a 15-shot magazine from a Glock 19 9mm:

Glock 26 with a 17-shot magazine from a Glock 17:

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And yes, even though it looks a bit silly, the Glock 26 (like all the other 9mm Glocks) can use the extended-capacity Glock 18 magazine:

To summarize, Glocks have several different options for increasing their magazine capacity, and the smaller (shorter) they are, the more options they have available. Here is a partial roundup of the magazines that I have used in my Glock 26, with flawless reliability:

Not pictured, but still a viable option, would be the 17-shot Glock 17 magazine with a "+" floorplate, for a total capacity of 19 rounds. Adding a "+" floorplate to the 15-shot Glock 19 magazine IS an option, but it would only get you 17 shots (the same as an unmodified Glock 17 magazine, which would be less expensive).

WARNING: Before depending on any larger- or extended-capacity magazine in any pistol for serious uses, be sure to test it for safe fit and functioning, with the exact ammunition you intend to use. Not all guns will work reliably with all possible magazine/ammunition combinations.

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The full-size Glocks in 9mm/.40/.357 have always had smooth-faced triggers. Starting with the introduction of the compact (G19-size) handguns, compact (and later, sub-compact G26/G27/G33 guns) had a trigger with a grooved face. This feature was added to give the smaller models enough points under the "points system" import rules required by the Gun Control Act of 1968. To be allowed into the U.S., points are awarded based on features such as size, weight and caliber (generally, bigger is better), adjustable target sights, and grooved target-shooting-style triggers. Without the grooved trigger, the smaller Glocks could not be legally imported.

Glock trigger styles, smooth-faced on the left, grooved on the right:

After using Glocks with both smooth- and grooved-face triggers, many shooters find they prefer the feel of a smooth trigger; others just want the same style trigger in all their guns so they handle in a similar manner. Based on this, many of the compact/sub-compact guns' grooved triggers are replaced by users with smooth-faced trigger assemblies made for the larger full-size models, which are interchangeable. Although the replacement of the trigger assembly is not a difficult task, there are a series of safety checks which should be performed prior to using a Glock that has had the trigger (with attached trigger bar) replaced. If you don't know how to perform these safety checks, it is recommended that you have a gunsmith or Glock armorer do the replacement, to ensure safe operation and no unpleasant surprises during use.

Smooth and grooved trigger assemblies, including the attached trigger bar:

One of the interesting things about the long-slide Glock 17L competition pistol, is that Glock was able to engineer it to reliably function with the same recoil spring assembly used on the shorter Glock 17, despite the longer slide and barrel. This was done by removing as much excess metal as possible from the 17L slide assembly, by machining cut-outs and recesses in non-critical areas of the slide. By getting the weight down to nearly the same weight of a model 17 slide/barrel assembly, the same recoil spring could be used without compromising reliability.

The photos below are of a late Gen1 model 17L and early Gen2 model 17, manufactured a little over a year apart (side-profile photos of these two guns can be seen in posts number 7 and 18, above). Although the frames were quite a bit different, as far as I can determine, there were no changes made to the basic Glock 17 slide assembly between these two models, so any differences are attributable to the machining required to lighten the slide for the model 17L.

The top view shows the most obvious difference; the "window" in the top of the slide between the front sight and the ejection port. This was not only for weight reduction; some 17L models were shipped with an optional ported barrel, which directed hot expanding gasses up through ports cut into the barrel, and out through this window, helping to reduce/suppress the tendency for the muzzle to rise or flip during recoil. On later Gen3 17L pistols, this window has been moved or reduced slightly in length to allow a larger base for mounting longer front sights, such as the light-pipe sights often used in action-shooting competitions.

Flipping the slides over, we see the first major internal weight-reduction cut, along the lower-right edge of the 17L slide. This cut is deep, extending very close to the top surface of the slide.

On both sides of the slide where the breech (or chamber) portion of the barrel slides up and down during cycling, the slide is much thicker, to guide the barrel into position as the slide opens and closes. These thick areas were reduced by machining the solid slab areas into "ribs", removing metal in two different spots so the barrel still would be correctly guided into position, but without using all the metal left in place on the model 17 pistols.

Right-side view (17L slide at the bottom):

and left side view (17L slide at the top):

These lightening cuts allowed the early Glock 17L competition pistols to exhibit the same high level of reliability as the service-grade model 17s, with the added perks of an extended sight radius and a lighter trigger connector, making them one of the first factory-issued long-slide high-capacity competition pistols on the market.

Glock was one of the first handgun manufacturers to offer factory-made ported/compensated autopistols. Although there are differences between installing a compensator on a handgun, and porting the barrel/slide assembly, Glock seems to use the terms almost interchangeably, and so will I.

The purpose of a ported or compensated handgun is to reduce the recoil-related upward flip of the barrel when it is fired, thereby getting the sights back on target (or onto the next target) as quickly as possible. Porting can be done in different ways, and Glock has used several different methods on various models over the years.

The first ported Glock was the model 17L. Early versions had a barrel ported with three angled slots, to direct some of the powder gasses upward, reducing the muzzle flip when fired. Not all 17L models were ported; some had conventional (non-ported) barrels. Although Glock has never officially acknowledged a problem with the 17L ported barrels, there were reports from some users that the thin area between the ports would sometimes crack. All Gen2 and Gen3 versions of the 17L were only sold with non-ported barrels, which could be interpreted as a confirmation that there was some kind of difficulty with the earlier Gen1 17L ported barrels.

Early Gen1 G17L with ported barrel:

Side view of barrel (removed from slide) to show profile of the ports:

After discontinuing the ported Gen1 17L models, Glock didn't offer any ported models again until 1994. The new-for-1994 G24C long-slide was the same size as the 17L, but a little heavier (as were all .40 caliber versions of 9mm Glocks). It had a different arrangement and shape of ports on the barrel, but the ports were still centered on the barrel and still vented upward through the cutout in the top of the slide. The ports were also different sizes, with the first one (closest to the breech) being the smallest, the second being slightly larger, and the last two being the largest and equal in size.

Glock 24C:

G24C port shape and location:

The G24C was produced from 1994 to about 1998, although there are reports that occasional short production runs of non-ported (G24) models were released after this period. Although the G24C has been listed in the annual Glock catalog for the last several years, it appears actual production has been slow-to-nonexistent.

In the past, Glock also offered G24C slide/barrel assemblies for sale separately, so owners of service-length G22 .40-caliber pistols could "upgrade" to a target-style top end to make their Glocks more versatile. Ads for these slide/barrel assemblies can be seen in some of the late 1990s "Glock Annual" or "Glock Autopistol" magazines/catalogs.

EDIT: The 24C shown above is a Gen3 model. Some early Gen2 versions of the ported G24 were not marked "24C" on the slide; they were marked the same as the unported models ("24"), and the box label had a "-P" after the model number, designating a ported barrel.

Beginning in late 1996 or early 1997, a new style of porting became available on full-size and compact Glocks. Different from either of the previous styles, it consisted of two ports side-by-side at approximately 11 o'clock and 1 o'clock positions on the top of the slide/barrel assembly. These ports are oval-shaped, elongated front-to-rear, and the corresponding cuts in the slide are considerably longer than the ports, allowing gas to continue to vent through the ports even as the slide unlocks and begins to travel to the rear. The V-shaped offset position of the ports prevents the exiting gasses and any associated flash from affecting the sight picture during firing in low light; in fact, most visible flash occurs above the slight plane, and is far more visible when viewed from the side vs. directly behind the ports, where the shooter is located. This type of porting has been used on Gen2 and Gen3 Glocks, and is currently available only on Gen3 models; as of this date, no ported Gen4 models have been seen or announced.

EDIT: In late May 2014, there was a report (with photos) of a short run of ported Gen4 Glocks for the European market. This was only a few models, and when someone asked Glock USA about it, they said it was a limited run, with no plans for expansion or any similar offerings here in the US. The photos of the Gen4 Glocks showed the V-type of porting seen in this post.

I read in this thread about a Gen 3 witout the rail and without hand grooves. I live in MA and I own a 3 pin glock 23 that does not have a light rail or finger grooves on the front of the frame und the trigger guard. I had to add an aftermarket rubber hand grip to get the finger bumps.

I read in this thread about a Gen 3 witout the rail and without hand grooves. I live in MA and I own a 3 pin glock 23 that does not have a light rail or finger grooves on the front of the frame und the trigger guard. I had to add an aftermarket rubber hand grip to get the finger bumps.

That is a Gen 2. The "third pin" was added to handle the .40 round.

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Since this is the knowledge thread, I will ask here. Did the Gen1 17s come with un-captured guide rods? I bought one used and its supposedly all factory. Just I can't seem to find anything on the guide rods.

Since this is the knowledge thread, I will ask here. Did the Gen1 17s come with un-captured guide rods? I bought one used and its supposedly all factory. Just I can't seem to find anything on the guide rods.

Yes, I believe all Gen1 Glock model 17 9mms came with the old-style uncaptured recoil spring and rod. Actually, in the full-size models, I don't think the changeover happened until the Gen2 guns were in production, as my fairly early Gen2 17 also has an uncaptured spring.

The old-style Glock-manufactured uncaptured springs were made of flat spring wire, and the rod was polymer, with a tiny hole in the muzzle end of the rod. I don't think the early rods or springs were marked in any manner.

Springs for the full-size models in 9mm, .40, and .357 are backwardly compatible from Gen3 to Gen1. So, if you need a replacement spring, you can use any Gen1/Gen2 uncaptured spring and rod, or Gen2/Gen3 captured recoil spring assembly (RSA), that was made for a full-size Glock in any of the above calibers.

Yes, I believe all Gen1 Glock model 17 9mms came with the old-style uncaptured recoil spring and rod. Actually, in the full-size models, I don't think the changeover happened until the Gen2 guns were in production, as my fairly early Gen2 17 also has an uncaptured spring.

The old-style Glock-manufactured uncaptured springs were made of flat spring wire, and the rod was polymer, with a tiny hole in the muzzle end of the rod. I don't think the early rods or springs were marked in any manner.

Springs for the full-size models in 9mm, .40, and .357 are backwardly compatible from Gen3 to Gen1. So, if you need a replacement spring, you can use any Gen1/Gen2 uncaptured spring and rod, or Gen2/Gen3 captured recoil spring assembly (RSA), that was made for a full-size Glock in any of the above calibers.

Thanks. I ran my RTF2 17 spring in my Gen1 for a couple hundred rounds, but next outing I am going to use the uncaptured spring & rod.

it looks like the first Gen3 G17 shows up in the CME serial number range, with a born-on date of November 1997, with a Gen3 G22 (CNW prefix) and a G19 (prefix CPH) showing up just a few months later in January of 1998.